Add Transifex configuration.

Add a configuration file for Transifex (a collaborative translation site) and
add a *.po file for the source language (en).
password_change_done - using correct template
Merge pull request #338 from mislavcimpersak/master

password_change_done - using correct template
Changed username auth backend to be case insensitive.
Merge pull request #340 from Gussy/case_insensitive_auth_backend

Username case inconsistencies
Merge pull request #332 from jnns/master

Use Transifex for translation.
Updated translations
Custom model without first/last name (closes #329)
I couldn't figure this out why it was not working till I actually looked at the source.

This change might save some beginner developers a few hours of time when see they see that their custom account adapter is not working. I've edited where ever I felt the need for it.
Merge pull request #351 from manuganji/master

Adding `self` as the first argument in the docs for over riding methods in custom adapters
django requirements should start with capital letter in setup.py
Merge pull request #352 from bezidejni/master

Django package requirement should start with capital letter in setup.py
Fix login link on socialaccount login cancelled page
Merge pull request #353 from heryandi/master

Fix login link on socialaccount login cancelled page
Allow signup super form to order email and username fields.
Merge pull request #354 from grue/master

Allow the base signup form to order email and username fields.
Remove unnecessary and mostly documentation links
Merge pull request #357 from pydanny/remove-unnecessary-doc-index-links

Remove unnecessary and mostly documentation links
Added Polish translation.
Merge pull request #359 from sandlbn/master

Added Polish translation.